Light source device and liquid crystal display

Abstract

A light source device capable of realizing a color display having the high light-use efficiency with a simple configuration is provided. Provided is a light source device including a prism sheet disposed to face a plane to be irradiated, and to bend an incident light to a direction substantially orthogonal to an incident direction; a light source section separately emitting a plurality of color lights having wavelength regions different from each other so that each of the color lights enters into the prism sheet at a small angle with respect to an extending direction of the prism sheet; and a light source drive means for driving the light source section so that each of the color lights periodically scans the plane to be irradiated so as to perform the line-sequential irradiation operation.

1. A light source device comprising:
 a prism sheet disposed to face a plane to be irradiated, and to bend an incident light to a direction substantially orthogonal to an incident direction; 
 a light source section separately emitting a plurality of color lights having wavelength regions different from each other so that each of the color lights enters into the prism sheet at a small angle with respect to an extending direction of the prism sheet; 
 a light source drive means for driving the light source section so that each of the color lights periodically scans the plane to be irradiated so as to perform a line-sequential irradiation operation; and 
 a light guide section (i) disposed between the light source section and the prism sheet, (ii) configured to separately guide each of the color lights to the prism sheet and (iii) haying an inclination with respect to the prism sheet so that each of the color lights separately enters the prism sheet at the small angle. 
 
     
     
       2. The light source device according to  claim 1 , wherein the light guide section is configured by stacking a plurality of light guide plates, each of the light guide plates being configured to guide each of the color lights to the prism sheet. 
     
     
       3. The light source device according to  claim 1 , wherein a thickness of each of a plurality layered light guide plates is made smaller than an irradiation line width of each of the color lights irradiated from the light source section to the light guide section during the line-sequential irradiation operation. 
     
     
       4. The light source device according to  claim 1  applied to a liquid crystal panel modulating the incident light on the basis of a(n) image signal, wherein the light source device is configured as a backlight system which emits each of the color lights as the incident light from the light source section toward the liquid crystal panel as the plane to be irradiated, the light source section being line-sequentially controlled by the light source drive means. 
     
     
       5. The light source device according to  claim 1 , wherein the small angle is about 3 degrees. 
     
     
       6. The light source device according to  claim 1 , wherein the prism sheet has a flat surface on a plane side and a prism in triangle shape surface on a light guide section side. 
     
     
       7. A liquid crystal display comprising:
 an irradiation means for emitting a light, the irradiation means having a prism sheet and a light source section disposed between the irradiation section and the prism sheet; 
 a liquid crystal panel modulating the light emitted from the irradiation means on the basis of an image signal and disposed to face the prism sheet; and 
 a light source drive means for driving the light source section so that each of the color lights periodically scans the liquid crystal panel so as to perform a line-sequential irradiation operation, 
 wherein, 
 the prism sheet bends an incident light to a direction substantially orthogonal to an incident direction, and 
 the light source section is configured to separately emit a plurality of color lights having wavelength regions different from each other at a small angle with respect to an extending direction of the prism sheet so that each of the color lights separately enters into the prism sheet at the small angle. 
 
     
     
       8. The liquid crystal display according to  claim 7  configured as a liquid crystal projector comprising:
 a projection means to project the light emitted from the light source section and modulated by the light crystal panel to a screen. 
 
     
     
       9. The liquid crystal display according to  claim 7 , wherein the small angle is about 3 degrees. 
     
     
       10. The liquid crystal display according to  claim 7 , wherein the light source section includes a light guide configured to separately guide each of the color lights to the prism sheet and having an inclination with respect to the prism sheet so that each of the color lights separately enters the prism sheet at the small angle. 
     
     
       11. The liquid crystal display according to  claim 10 , wherein the prism sheet has a flat surface on a liquid crystal panel side and a prism in triangle shape surface on a light guide side. 
     
     
       12. A method of realizing a color display with a light source device, the method comprising:
 facing a prism sheet toward a plane to be irradiated: 
 bending an incident light to a direction substantially orthogonal to an incident direction using the prism sheet: 
 emitting a plurality of color lights having wavelength regions different from each other using a light source section so that each of the color lights enters into the prism sheet at a small angle with respect to an extending direction of the prism sheet; 
 driving the light source section with a light source drive section so that each of the color lights periodically scans the plane to be irradiated so as to perform a line-sequential irradiation operation; and 
 separately guiding each of the color lights to the prism sheet with a light guide section (i) disposed between the light source section and the prism sheet, and (ii) having an inclination with respect to the prism sheet so that each of the color lights separately enters the prism sheet at the small angle. 
 
     
     
       13. The method according to  claim 12 , wherein the small angle is about 3 degrees. 
     
     
       14. The method according to  claim 12 , wherein the prism sheet has a flat surface on a plane side and a prism in triangle shape surface on a light guide section side. 
     
     
       15. A method of realizing a color display with a liquid crystal display, the method comprising:
 emitting light using an irradiation section having a prism sheet and a light source section disposed between the irradiation section and the prism sheet; 
 modulating the light emitted from the irradiation section on the basis of an image signal using a liquid crystal panel disposed to face the prism sheet: 
 bending an incident light to a direction substantially orthogonal to an incident direction using the prism sheet; 
 separately emitting a plurality of color lights having wavelength regions different from each other at a small angle with respect to an extending direction of the prism sheet using the light source section so that each of the color lights separately enters into the prism sheet at the small angle: and 
 driving the light source section using a light source drive section so that each of the color lights periodically scans the liquid crystal panel so as to perform a line-sequential irradiation operation. 
 
     
     
       16. The method according to  claim 15 , wherein the small angle is about 3 degrees. 
     
     
       17. The method according to  claim 15 , wherein the light source section includes a light guide configured to separately guide each of the color lights to the prism sheet and having an inclination with respect to the prism sheet so that each of the color lights separately enters the prism sheet at the small angle. 
     
     
       18. The method according to  claim 17 , wherein the prism sheet has a flat surface on a liquid crystal panel side and a prism in triangle shape surface on a light guide side.